Impact press



Oct. 4

, 1938. l.. K, DAvls 2,132,148

IMPACT PRESS Filed Jan. 30, 1937 2 Sheets-Sheet 1 Fl 'E l V3845 +o 444,8 57| 55 5 l 4b q zo, 'e '5 |7 24 L5 3o `zo u y t! 'u i o 5 l l l 4 hl INVENTOR.

LEWIS K .DFW/5.

A TTORNY L. K. DAVIS IMPACT PRESS Oct. 4, 1938.

2 Sheets-Sheet 2 Filed Jan. 50, 1937 muni l IN V EN TOR.

LEWIS K. .DAV/5,

A TTORNEY Patented oct. 4, 193s UNITED sfrA'ras IMPACT PnEss Lewis K.Davis, Hampton, N. J., assignor to Grace P. Davis, Hampton, N. J. f/ YApplication January 30, 1937, Serial No. 123,223

12 Claims.

This invention relates to improvements in impact presses of the typesuitable for splicing cable and performing other operations involvingthe forceful driving of a hammer, plunger or die, into engagement withwork supported in operative relation to the hammer, plunger or die. Inmy prior co-pending application, Serial No. 63,072, filed February l0,1936, I have described an impact press for this purpose in which themotive force is supplied by the combustion of a charge of propellentpowder. The present invention contemplates certain improvements andrenements in the device of my former application.

It has been found, as a result of extensive testing under actual workingconditions, that the temperatures and pressures developed within thecylinder of a device of this character are such as to cause undesirableerosion of the surfaces of the cylinder and/or the head of the piston.

The present invention contemplates novel means and combinations ofmeans, first, for reducing and controlling initial pressures; andsecond, for effecting a reduction in pressure immediately uponcompletion of the power stroke of the piston;

thereby obviating the erosion due to the maintenance of pressures in thecylinder at a time when such pressure does not serve any useful purpose.

'Ihe invention further contemplates a new and improved breech mechanismwhich securely and effectively closes the breech end of the iiringchamber or cylinder and at the same time is readily removable to effectreloading.

The invention further contemplates a barrel or cylinder which isremovably held in the machine frame and may be quite readily removed andreplaced when excessive use has impaired its functioning.

In the drawings:

Fig. 1 is a side elevation, partly in section, of

an impact press embodying the present invention.

Fig. 2 is a plan view of the same press.

Fig. 3 is a front elevation of the press.

Fig. 4 is a horizontal section substantially on the line 4-4 of Fig. 1.

The machine comprises a main fra'me, identied generally bythe numeralI0, the lower portion of lwhichis formed in a c -shape to provide a worksupporting anvil. The upper portion of the frame comprises a lateralextension II forming a handle. The body I2 of the frame above the anvilforming portion is of generally cylindrical exterior shape with suchreinforcing and part supporting extensions and projections as may bedesirable. This portion of the frame comprises a cylindrical bore andcounterbore adapted to receive and support the barrel or cylinder I3,the lower end of said cylinder resting on the shoulder I4 joining thebore through the lower end of the 5 frame I2 with the larger counterboreextending the greater part of the lengtliof the body of said frame.

In my prior co-pending application, aboveidentified, the machine framecomprises a cylin- 10 drical bore which receives the hammer or piston.When the wall of this bore becomes pitted or eroded it is necessary todiscard the entire frame. According to the present invention, thecylinder or barrel is made a separate member supported ll and held inthe frame proper in the manner just described; thus, a worn or erodedcylinder is capable of ready replacement.

The barrel or cylinder I3 comprises at its upper end a chamber I5adapted to receive a cartridge 20 such as I6. The chamber I5communicates with the larger cylindrical chamber I1 adapted to receive apiston-like' member I8, which member,

'according to the embodiment of the invention illustrated in thedrawings, is provided with a 25 hammer face particularly designed toimpact and indent a cable splicing sleeve of a material such as copperor brass. The piston I8 is yieldingly held in retracted or elevatedposition in the cylinder I3 by suitable devices, one form of which 30may be as follows:

At an appropriate position in the length of the piston a circular grooveI9 is formed in its periphery. -When the piston is elevated this groovestands opposite a somewhat deeper groove 20 in 35 the interior wall ofthe cylinder I3. Within the grooves I 9 and 20 is placed a brokenelastic metal ring 2 I, the stock of such ring preferably being ofcircular cross section, so that the ring may be spread or cammedoutwardly by engagement with 40 the camming upper surface of the grooveI9. The ring tends to spring inwardly into the groove I9, which grooveis of such depth that when it is occupied by the ring the outer portionof the ring projects outwardlyinto the groove 20. When 45 suiiicientdownward force is exerted on the piston, the ring will be cammed out ofthe groove I9 into the groove 20, the periphery of the piston slidingthrough it in the upward and downward movement of the piston. The partsare so propor- 50 tioned and the ring is of such rigidity as to relquirea substantial build up of pressure above the piston before the ring isdisplaced and the piston' permitted to move. This type of pistonrestraining means has for certain types of work 55 been found aneffective substitute for the shear pin illustrated in my applicationabove-identied and also in my `Patent No. 2,030,686

It has likewise been discovered that .erosion of cylinder and piston canbe substantially eliminated without loss of emciency by providing a ventthrough the wall of cylinder I3 and the surrounding frame I2, which ventis opened when the piston reaches its lowermost or advanced position.When the piston has reached this position the blow has been delivered tothe work upon the anvil and, while it is desirable to prevent animmediate rebound of the piston from the work, it has been foundpossible to so vent the cylinder as to materially relieve burning thecylinder and piston while still maintaining such a pressure on thepiston as will preclude an immediaterebound of the piston and aconsequent springback of the work upon the anvil which has been deformedby the piston. Accordingly, the present invention provides an aperture22 extending transversely through the wall of cylinder I3 just above thelowermost position of piston I8, and an aperture 23 through the wall ofthe frame I2 in alignment with the aperture 22.

Since tools of this character may be used in places where the aircontains considerable amounts of inflammable gases, it is desirable todamp and extinguish such powder combustion flame as might otherwise beprojected into the air. For this purpose, there is associated with theapertures 22 and 23 a ame arrester which may be constructed as follows:

The adjacent portion of frame I2 is formed into a suitable boss 24 whichis counterbored and threaded to receive a threaded portion 25 of a llamearrester identified generally by the numeral 28 and comprising a passage21 aligning with the aperture 23. The passage 21 is suitably divided todistribute and transmit the flame passing therethrough to a chamber 28which is lled with a suitable flame arresting and absorbing material. Anumber of thicknesses of copper screen have been found very effectivefor this purpose. In

l the embodiment illustrated in the drawings, the

chamber 28 is occupied by several superposed layers of copper s creen of100 mesh. The outer portion of the body 26 of the flame arrester isthreaded to receive a cap 30 which covers the chamber 28, the portion ofsaid cap over such chamber comprising a plurality of apertures such as3| through which the gases cooled by the ame arrester finally escape.The joint between the threaded end 25 of the flame arrester and the boss26 of the frame may be sealed by a rubber gasket 32, said gasket beingapertured to provide a passage from aperture 23 to flame arresterpassage 21. A device of this character has been found to be veryeffective in reducing burning and erosion of the piston and cylinderwithout the undesirable transmission of flame and heated gases to theexterior.

'Ihe improved breech mechanism may be constructed as follows:

The upper end 35 of the frame I2 conforms to the exterior configurationillustrated in Fig. 2, the cylinder receiving bore extending through theupper end of the frame and being intersected by a transverse slot ofgreater width and length than the cylinder bore and adapted to receiveatransversely moving breech block 36. The breech block comprises anaperture adapted to receive a firing pin 31, firing pin retractingspring 38, and firing pin holding nut 39. 'Ihe firing pin is adapted tobe struck by a hammer 310 pivoted at 31| and controlled by a trigger312. Said breech block is heldin breech closing position and againstmovement in its slot in the frame by a plunger i0 comprising an enlargedfoot 4| adapted to be received in a recess d2 in the surface of theupper end of the cylinder I3, said cylinder being, as shown in thedrawings, immediately adjacent the breech block. 'I'he foot I is urgedinto recess 42 by suitable means such as a spring 83 encircling theshank of plunger 40. Means are provided for withdrawing the foot @I andthus unlocking the breech for movement transversely out of the frame,which meansA may comprise a head M on the plunger 40 adapted forengagement by the forked end 45 of a lever pivoted at d6 in ears 41upstanding from the breech block 38. 'I'he front end d8 of saidleverforms a handle, the depression of which elevates the plunger fill,this operation being facilitated. by a handle 89 projecting outwardlyfrom the body 36 of the breech block and adapted to be grasped alongwith handle d8. By grasping these handles and depressing handle 48,plunger d is lifted to withdraw foot 6I from recess 42 and thereupon thebreech block can be moved laterally out of the slots in frame l2 topermit the insertion of a cartridge into chamber I5.

It is to be understood that this invention is not limited to the detailsof construction illustrated in the accompanying drawings but includessuch modifications thereof as fall within the scope of the appendedclaims.

What is claimed is:

1. An impact press comprising a frame having an aperture adapted toreceive and support a replaceable cylinder, a cylinder in said framecomprising a bore adapted to receive a piston, a piston in saidcylinder, means associated with said frame adapted to hold and ignite apiston propelling charge, and means for retarding movement of saidpiston comprising matching grooves in the peripheries of said cylinderand said piston respectively and a ring elastically held in both saidgrooves and displaceable from one of them by pressure on said piston.

2. An impact press comprising a frame apertured to receive a replaceablecylinder, a cylinder in said frame, a piston in said cylinder, means forpropelling said piston from a normal position through a power stroke,and means for initially retaining said piston against the force of saidpropelling means comprising a peripheral groove in said cylinder, amatching peripheral groove in said piston, a ring of elastic materialnormally lresting in said matching grooves and thereby retaining thepiston in normal position but adapted to be displaced out of one of saidgrooves when the force tending to propel said piston from normalposition exceeds a predetermined amount.

3. An impact press comprising a frame apertured to receive a replaceablecylinder, a cylinder in said frame, a piston in said cylinder, means forclosing said cylinder comprising a transverse slot in said frame, abreech block adapted to be slidably received in said slot and to abutthe upper end of said cylinder, and means for retaining said breechblock in said slot.

4. An impact press comprising a frame apertured to receive a replaceablecylinder, a cylinder in said frame, means for closing one end of saidcylinder comprising a transverse slot in said frame open at one end, abreech block adapted to be received in said slot, and means forretaining said breech block in cylinder closing position comprising aplunger extending through said breech block and a recess in said frameadapted to receive a portion of said plunger.

5. An impact press comprising a frame apertured to receive a replaceablecylinder, a cylinder in said frame, means for closing one end of saidcylinder comprising a transverse slot in said frame open at one end, abreech block adapted to be received in said slot, means for retainingsaid breech block in cylinder closing position comprising a plungerextending through said breech block and a recess in said frame adaptedto receive a portion of said plunger, and means for retracting saidplunger to permit removal of said breech block comprising a leverpivoted to said breech block and engaging said plunger.

6. An impact press comprising a frame apertured to receive/a replaceablecylinder, a cylinder in said frame, means for closing one end of saidcylinder comprising a transverse slot in said frame open at one end, abreech block adapted to be received in said slot, a spring pressedplunger extending through said breech block, a recess in said frameadapted to receive a portion of said plunger, and means for retractingsaid plunger against the force of its spring comprising a lever pivotedto said breech block and engaging said plunger.

7. An impact press comprising a frame apertured to receive a replaceablecylinder, a cylinder in said frame, means for closing one end of saidcylinder comprising a transverse slot in said frame open at one end, abreech block adapted to be received in said slot, a spring pressedplunger extending through said breech block, a recess in said frameadapted to receive a portion of said plunger, and means for retractingsaid plunger against the force of its spring comprising a lever pivotedto said breech block and engaging said plunger and a handle projectingfrom said breech block and adapted to be grasped by the operator alongwith said lever.

8. An impact press comprising a frame apertured to receive a replaceablecylinder, a. cylinderv in said frame, a piston in said cylinder, meansfor retaining said piston in normal position comprising matching groovesin the periphery of said cylinder and said piston respectively and anelastic ring normally occupying portions of both of said grooves butadapted to be displaced into one of them by adequate pressure to permitmovement oi.' the piston, means for closing said cylinder above saidpiston comprising a transverse groove in said frame open at one end, abreech block slidably received in said groove and abutting saidcylinder, pressure generating means carried by said breech block, andmeans for retaining said breech block in cylinder closing positioncomprising a plunger extending through said breech block and a recess insaid framel adapted to receive a portion of said plunger.

9. A unitary portable tool for the splicing oi' cables and the likecomprising a work support, a piston cylinder mounted in alignment withsaid work support, said piston cylinder being held in a frame rigidlyconnected to said work support, a piston in said cylinder, pressuregenerating means for moving said piston comprising an explosive device,means for ring said explosive device, an exhaust vent for the gases ofexplosion extending through said cylinder and said frame, said ventbeing normally covered by said piston and opened by the movement of saidpiston, and means associated with said vent for preventing the passageof iiame while permitting the escape of gas, said means comprising abody of foraminous heat conducting material and a housing therefor.

10. A unitary portable tool for the splicing of cables and the likecomprising a work support, a piston cylinder mounted in alignment withsaid work support, said piston cylinder being held in a frame rigidlyconnected to said work support. a piston in said cylinder, pressuregenerating means for moving said piston comprising an explosive device,means for firing said explosive device, an exhaust vent for the gases ofexplosion extending through said cylinder and said frame, said ventbeing normally covered by said piston and opened by the movement of saidpiston, and means associated with said vent for preventing the passageof iiame while permitting the escape of gas, said means comprising ahousing threaded to said frame, a body of ioraminous metal in saidhousing, and a perforated cover threaded to said housing.

1l. In a unitary portable tool for the splicing of cables and the like.the combination with a work support, a piston cylinder mounted inalignment with said work support, said piston cylinder being held in aframe rigidly connected to said work support, a piston in said cylinder,pressure generating means for moving said piston comprising an explosivedevice, and means for nring said explosive device; of means forpreventing erosion of said piston by the gases of explosion andpermitting the escape of said gases from said cylinder while preventingthe escape of ame, said means comprising aligned apertures in saidcylinder and said frame. and a ame arrester secured to said frame, saidflame arrester comprising a body of foraminous metal and a housingtherefor.

12. In a unitary portable tool for the splicing of cables and the like,the combination with a work support, a piston cylinder mounted inalignment with said work support, said piston cylinder being held in aframe rigidly connected to said work support, a piston in said cylinder,pressure generating means for moving said piston comprising an explosivedevice, and means for firing said explosive device; of means forpreventing erosion of said piston by the gases of explosion andpermitting the escape of said gases from said cylinder while preventingthe escape of ame, said means comprising aligned apertures in saidcylinder. and said frame, and a name arrester secured to said frame,said flame arrester comprising a housing threaded to said frame, a bodyof foraminous metal in said housing, and a perforated cover threaded tosaid housing.

LEWIS K. DAVIS.

